The landing site of a European spacecraft that was supposed to make a historic touchdown on Mars this week has been identified in images that suggest the probe suffered a violent collision at the surface.
Images from Nasa Mars Reconnaissance Orbiter show a large “fuzzy dark patch” that scientists think was caused by huge plumes of dust thrown up in a high-speed crash - and may even indicate the probe exploded on impact. Theprobe is believed to have gone down with full fuel tanks far faster than planned because its retrorockets, intended to slow it down, fired for only a few seconds before switching off prematurely.
A second, brighter, surface feature is thought to be the 12-metre-wide parachute, which the Schiaparelli lander jettisoned during descent.
The latest observations confirm what most European Space Agency (ESA) scientists were already resigned to: that what was supposed to be a historic first scientific mission on Mars for Europe had been scuppered at the last moment. The rapid location of the craft is likely to come as a relief, however, and will help with the forensic analysis that is already underway.
The parachute was released from Schiaparelli ahead of its final landing sequence, during which its nine thrusters should have slowed it to a walking pace just above the surface.
But data beamed back from the lander to its mothership, the Trace Gas Orbiter, show that its thrusters only fired for three or four seconds rather than 30 seconds as intended. Schiaparelli continued transmitting for a further 19 seconds before going silent.
Scientists now think that after the thrusters switched off, Schiaparelli plummeted in freefall from a height of between two and four kilometres, and hit the surface at more than 300 km (186 miles) per hour. The fuzzy patch, which is roughly 15 by 40 metres in size, would indicate the halo of disturbed surface material.
“It is also possible that the lander exploded on impact, as its thruster propellant tanks were likely still full,” ESA said in a statement. “These preliminary interpretations will be refined following further analysis.”
A powerful camera called HiRISE on board the Nasa probe will take more detailed images of the features next week.
Speaking before the lander was identified, Jorge Vago, the ExoMars project scientist, said it was critical for the team to work out what went wrong. “Of course we are disappointed that the landing didn’t go well ... The silver lining is we have a lot of detailed information,” he said. “I think we will be able to explain it.”
“It will take a few weeks to work out what happened,” he added. “People are very careful when something bad happens like this.”
Prof David Southwood, a space scientist at Imperial College London, noted that Mars missions seem particularly prone to mishap. “If one were superstitious, one would say it is a return of the Mars gremlin.” However, he added that the failed landing attempt should not detract from the more important element of the mission, which was always intended to be orbiter’s measurements of trace gases, such as methane, which might indicate the presence of alien life.
“Time and again the US Mars program faced failure and, like Robert the Bruce, straightforwardly went on with the task of overcoming setback,” he said. “Space exploration is tough. As long as we believe in its societal worth, Europe needs to do the same.”
The position of the dark mark shows that Schiaparelli impacted about five kilometres west of its intended landing point, but well within the 100 x 15 km landing ellipse it was targeting.
